“You might have won good fortune making the film,” he wrote, “But you failed miserably when it comes to basic social etiquette.”

“I wonder what Yingluck Shinawatra thinks of Chinese men now,” he added.

This Weibo post received 6,000 comments hours later, mostly from Lost in Thailand fans defending Xu.

“Director Xu was apparently wearing simple and comfortable clothes,” one fan wrote, “There was nothing wrong with him just being himself.”

Xu Jingbo disagreed.

In an interview with SCMP.com on Friday, Xu Jingbo argued that the director was not “just representing himself.”

“In such a formal occasion, he was also representing Chinese artists and men,” he said, “It’s improper and rude for him to roll up sleeves and expose his chest like that.”

Xu Jingbo then referred to a recent example of Hong Kong action star Jackie Chan, who had dressed in a traditional Chinese costume to attend the NPPCC session in Beijing.

“A man with taste should know better,” he said. “Be it a suit or traditional dress.”

Although Thailand is one of the most popular tourist destinations among Westerners, it still adheres to strict rules on dress when it comes to the country's leaders and temples. Thailand's monarchy in particular commands the respect and reverence of the Thai people. When tourists visit the royal palace in Bangkok they are warned that shirt sleeves, whether long or short, cannot be rolled up.

“The Cultural Revolution destroyed the traditional moral values, and it has been followed by a national money-making movement,” he said.

“I hope after this debate, people will start to reflect on our education and behaviour. We need to learn to wear proper clothes to show respect and character. A country cannot become strong simply by its GDP. It also needs tp show the world... the education and calibre of its people,” Xu said.